Coiler apparatuses are known, able to make coils of hot or cold semi-worked metal products from steel plants for example, or secondary processing products, such as for example rod, wire, tubular elements or suchlike; hereafter in the description, the various types of metal products are all included in the term rod.
It is known that for certain applications, rod has a non-uniform surface conformation, that is, there are edges or thicker zones on its surface which modify its section, even continuously.
It is also known that very often coiling takes place with the rod still hot or very hot, and it is also known that in these cases the section of the rod is sensitive to the variations in temperature.
Known coiler apparatuses can have a rod distributor coordinated with a rotating reel around which the spirals of the coil are formed.
The known reel normally has a mandrel associated with containing elements that define the width of the coil, of which at least one can be dis-assembled to extract the coil.
Two main configurations of coiler apparatuses are known: a first in which the reel is in a vertical position and a second in which the reel is in a horizontal position.
In both known configurations, the rod distributor is positioned laterally in a position kept substantially median to the axis of the reel.
The distributor normally has a cadenced to-and-fro movement on a plane that advantageously comprises the center line of the exit of the distributor and advantageously, although not necessarily, the axis of the reel.
In another solution, the distributor can have at least one motion on a plane that, on each occasion as coiling proceeds, is configured tangent to a cylindrical surface having a variable diameter and generated by the axis of the reel.
The distributor can be positioned continuously along the width of the coil and/or in the radial position of the spiral.
To manage the coiling, in the state of the art, knowing the nominal values of the section of the rod is not sufficient to obtain a sufficiently precise control of the formation of the coil, optimizing the filling rate and preventing overlapping and/or empty spaces between adjacent spirals.
Therefore, during coiling, known apparatuses are not able to coordinate optimally the functionality of either the reel or the distributor, so that the spirals are positioned in the desired manner, in particular with the desired angle, in relation to the optimization parameters indicated above, depending on the section and characteristics of the rod.
The incorrect disposition of the spirals during coiling generates imperfections in the coil obtained such as, for example, empty spaces, non-saturation and overlapping, partial or total, of the spirals.
Coils obtained with known apparatuses, due to their imperfections, have a low coefficient of density of the spirals, said coefficient being given by the ratio between the actual volume of the spirals and the volume of total bulk of the coil.
The high number of imperfections in coils obtained with known apparatuses, together with the low density of the spirals, makes it unproductive, also in terms of time, to use them in the production of meshes, cages, trellises, brackets etc. for reinforced concrete structures or suchlike or others.
Indeed, it is known that in the case of products to be used to obtain reinforced concrete, the coils are uncoiled with suitable machines that, during uncoiling, if there is an imperfection, must be stopped to allow the operator to intervene.
This causes a loss of time that slows down production and requires the intervention of operators, increasing costs which, due to the competitive market where the products obtained are sold, must remain as low as possible, or at any rate limited but with the same quality.
In order to improve the quality of the coils, some devices are known, for example ring-type control and adjustment devices, with which the rod distribution system cooperates.
These known devices, once positioned and calibrated, are able to measure some parameters including, for example, the rod distribution speed, and are able to use the information collected to control and manage the coiling.
However, these known devices are not very reliable in measuring the parameters, which is performed indirectly, by detecting tensions and/or currents induced in the ring.
This means that the consequent adjustment of the rotation speed of the reel is also not very precise, and/or the speed of movement and/or the positioning of the distributor.
Moreover, these known devices are not only unable to detect the section of the rod, they must also be constantly coordinated with the distributor and on each occasion must be replaced and/or adapted according to the section of the rod.
Winding devices are also known, applied for example for electric wires or other similar materials, but these do not adapt to managing the coiling of rod because such devices do not consider the variability of the section of the product to be wound during coiling, nor the variability of the section as a function of the temperature.
Indeed, during the coiling of rods, the rods have very variable sections between two consecutive spirals, and are disposed distanced from each other with a variable pitch.
This makes known winding devices, used in other technical fields, unsuitable for use for apparatuses for coiling hot or cold semi-worked metal products.
For example, documents U.S. Pat. Nos. 4,570,875 and 6,443,385 describe management devices associated with a coiler apparatus for cables with a uniform section, which do not adapt the action of the distributor in a manner coordinated with the rotation of the reel as a function of the variability of the section of the cable and the distance between two consecutive spirals, which in this case are always constant.
There is therefore a need to perfect the state of the art and make available a management method for a coiler apparatus, and the corresponding device, which overcome at least one of the disadvantages of the state of the art.
In particular, the purpose of the present invention is to improve the reliability of the direct detection of the instantaneous parameters of the rod and to condition the way the coil is formed on the basis of this.
Another purpose of the present invention is to improve the precision of the adjustment of the reel, in coordination with that of the distributor, to obtain desired positions both of the spirals and the layers of the coil, in order to prevent imperfections and/or residual tensions.
Another purpose is that the management device for coiler apparatuses according to the present invention can be applied to existing coilers, without necessarily being replaced and/or adapted according to the variability of the section of the rod.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.